Of Irish ancestry, this anatomist, physician, ethnologist and philosopher early became associated with the Academy, graduated from the University of Pennsylvania, then traveled a few years in Europe and the West Indies. Later he was appointed Professor of Anatomy in the Medical College at the University of Pennsylvania. His great work concerned the crania of vertebrates, especially of man, being the first scientist to use anthropometrical data in the study. His collection was enormous, specimens being received from all parts of the world. Crania were taken from battlefields, from alms houses, from jails, from Indian mounds and Egyptian tombs. He set forth beliefs that clashed with other scientists causing-a great controversy over the unity of the species of man.